The art is replete with all kinds of scaffolding and staging constructions, ranging from specially designed vertical staging pole systems, such as the “Alum-A-Pole System” of Harvey Industries, as described in their 1997 “Quality Building Products” catalog, to simpler proposals that employ ladders and step-ladders as supporting elements, as, for example, in U.S. Pat. No. 6,148,957 and the patent references cited therein; and also in U.S. Pat. No. 5,020,757 as another example, and even as far back as 1897 in U.S. Pat. No. 596,161 where a single vertical ladder scaffold was attached to a building oriented at right angles to the building. In the painting and construction trades, however, the almost universal practice has required that the elevated or erected ladder be supported inclined against the side wall of the building or other structure.
The discovery of the present invention resides in a novel way in which everyday ladders may actually be independently used to substitute for and to attain the advantages of the before-mentioned specialized and widely used vertical staging pole structures, but without the costs thereof.
The invention, furthermore, provides improved and safer and more facile operation then can be obtained by the use of ladders inclined against buildings; such being subject to the great dangers of lateral slipping and collapsing to the ground, or the outward slipping of the bottom foot ends of the ladder in response to the inherent forces pushing the legs away from the building as the ladder is ascended or descended. In addition, where one merely attaches horizontal staging platforms or boards between a pair of such ladders, the system is always inherently unstable and even tends to bounce in use. Still, this has been the best that the industry has had to use, particularly for home construction and repairs, and despite these limitations.
In accordance with the invention, on the other hand, pairs of every-day ladders may be rigidly held vertically spaced parallel to the side of the building in a structural assembly that admirably obviates all of the disadvantages, danger and limitations including those above described, residing in the use of ladders inclined against the building. To accomplish this result, a pair of braces is used, attachable between a rung near or at the top of the ladder and extending horizontally to opposed regions of the building. The braces are preferably of substantially V-shape, having horizontally extending fixed brace arms and diverging pivotable arms, all provided with fitments at their free ends for attachment to corresponding opposing regions of the building, thereby to provide a horizontal line of four-point engagement with the building that holds each ladder rigidly vertically and parallely spaced from the building. While the bottom foot ends of the ladder still rest at spaced positions on the ground, there is now no force laterally pushing them outward in the use of the ladder, as occurs in the case of inclined ladders.
Such spaced vertically mounted ladders are well adapted, in accordance with a further feature of the invention, to support scaffold staging planks and the like, and also guard-rail constructions, through the use of inverted L-shaped brackets. These brackets have upper and lower terminal hooks or collars on the vertically depending leg thereof for hooking attachment over ladder rungs and there against; with the other bracket leg projecting at right angles horizontally outwardly of the ladder or inwardly toward the building (or both, where a double bracket is used). At the free end of the horizontal perpendicular leg, a vertical upwardly extending post is preferably provided to contain a staging plank supported upon and between the horizontal perpendicular bracket legs of a pair of spaced ladders of the ladder staging. The posts can also serve to receive a hollow leg of a vertical side frame of a horizontal guard-structure, wherein transversely extending rails may extend between the ladders, as later discussed, and may be telescopically or otherwise extendable or collapsible depending on the lengths required. If desired, furthermore, the bracket posts may also help support other accessory devices including winch structures and depending safety net structures and the like.